FIX: Don't ask for notification permission until first one

app/assets/javascripts/discourse/lib/desktop-notifications.js.es6

@@ -1,6 +1,7 @@
 
 let primaryTab = false;
 let liveEnabled = false;
+let havePermission = null;
 let mbClientId = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
 let lastAction = -1;
 
@@ -15,25 +16,37 @@ let notificationTagName; // "discourse-notification-popup-" + Discourse.SiteSett
 function init(messageBus) {
   liveEnabled = false;
   mbClientId = messageBus.clientId;
-  requestPermission().then(function() {
+
+  if (!Discourse.User.current()) {
+    return;
+  }
+
   try {
     localStorage.getItem(focusTrackerKey);
   } catch (e) {
     Em.Logger.info('Discourse desktop notifications are disabled - localStorage denied.');
     return;
   }
+
+  if (!Notification) {
+    Em.Logger.info('Discourse desktop notifications are disabled - not supported by browser');
+    return;
+  }
+
+  if (Notification.permission === "granted") {
+    havePermission = true;
+  } else if (Notification.permission === "denied") {
+    havePermission = false;
+    return;
+  }
+
   liveEnabled = true;
-    Em.Logger.info('Discourse desktop notifications are enabled.');
   try {
-      // Permission is granted, continue with setup
+    // Preliminary checks passed, continue with setup
     setupNotifications();
   } catch (e) {
     Em.Logger.error(e);
   }
-  }).catch(function() {
-    liveEnabled = false;
-    //Em.Logger.debug('Discourse desktop notifications are disabled - permission denied.');
-  });
 }
 
 // This function is only called if permission was granted
@@ -139,6 +152,7 @@ function onNotification(currentUser) {
       const notificationBody = bodyParts.join("\n");
       const notificationIcon = Discourse.SiteSettings.logo_small_url || Discourse.SiteSettings.logo_url;
 
+      requestPermission().then(function() {
         // This shows the notification!
         const notification = new Notification(notificationTitle, {
           body: notificationBody,
@@ -150,7 +164,7 @@ function onNotification(currentUser) {
 
         function clickEventHandler() {
           Discourse.URL.routeTo(_notificationUrl(firstUnseen));
-        // Cannot delay this until the page renders :(
+          // Cannot delay this until the page renders
           // due to trigger-based permissions
           window.focus();
         }
@@ -161,6 +175,7 @@ function onNotification(currentUser) {
           notification.removeEventListener('click', clickEventHandler);
         }, 10 * 1000);
       });
+    });
   }
 }
 
@@ -191,6 +206,11 @@ function updateSeenNotificationDatesFrom(notifications) {
 // Utility function
 // Wraps Notification.requestPermission in a Promise
 function requestPermission() {
+  if (havePermission === true) {
+    return Ember.RSVP.resolve();
+  } else if (havePermission === false) {
+    return Ember.RSVP.reject();
+  } else {
     return new Ember.RSVP.Promise(function(resolve, reject) {
       Notification.requestPermission(function(status) {
         if (status === "granted") {
@@ -200,6 +220,7 @@ function requestPermission() {
         }
       });
     });
+  }
 }
 
 function i18nKey(notification) {